Initial reports claim the boys were 15 yards apart. Mastronardy said the victim was sitting in a go-kart/golf cart. He added that the parents were "nearby" for the incident; it was the four-year-old's mother who called 9-1-1 just before 7 p.m.

Toms River home where a 4-year-old boy fatally shot his 6-year-old friend (WCBS TV)

The victim was airlifted to Jersey Shore University Medical Center in Neptune.

Ocean County Prosecutor Joseph Coronato could not offer much detail on the incident, including where the gun was located inside the home. Mastronardy confirmed that more than one weapon was recovered inside the home. Officials canceled a 3 p.m. press conference scheduled for today.